Kerlen 2.4.13 and ramdisks

[Chris Fowler]

the image bein dd'ed is an ext2 file system image.  I eliminated most my
problems with
using 1 ram disk and no more.  2.2.X I used 3 ram disks.  In 2.4.X Im
linmited to 1.

The mount comand was an example.  If I used loopback, I would need to mount
it rw.  That would cause
problems during power failure.  That is whay I take a software image, dd it
to memory and mount as the rootfs.
If you lost power than you would only loose contents of memory.  If you
failed to issue "save" for the config, you would loose
working config too.

My unit requires no shutdown nor supports.  "restart" simply tells the
kernel to toggle the reset line
on the machine no processes is killed in the restart.  They just don't exist
anymore.  I want a rootfs that
is writable and not volatile.  If I loose it I do not care.  It is setting
on flash as an encrytped file.


]-----Original Message-----
From: Ian [mailto:Relativity at HumanHeuristic.com]
Sent: Tuesday, February 19, 2002 5:41 PM
To: Chris Fowler
Cc: linux-mtd at lists.infradead.org
Subject: RE: Kerlen 2.4.13 and ramdisks


> loopback would not allow me to write to the image while running it.
Making
loopback allows you to make modifications without dd'ing it in and out of
ramdisks (I used to use both methods for my initrd creation).

> the flash (upgrade) process more difficult.  The FS is ext2 and I do not
use
> mount.
I don't understand - you originally said;
                  "mount /dev/ram6  fails."

. but that said, I was mistaken too .. I meant the "-t" option ...
Ie; mount -t ext2 /dev/ram6 /tmp/flash


> The only way the kernel can mount this is by me putting it in memory
first.
> The only way to do that is with initrd.  It owkrs when initrd only places
> that data there.  When I try to download the *same* data from the network
> and put there it craps out.  I have to download the data first before I
can
If this is the case, where you download it and try to treat it like an
initrd, then
I'd be quicker to blame that process, than the ramdisk driver in 2.4.x --
particularly
when you say that it works as a straight initrd process (which is only
running
in ram anyway, as you know).

> place it in /dev/ram7.  TO do that I mount a ram fs at a upper limit of
> 32mb.  Download the file there then place it in /dev/ram7.  Just by using
> that memory as temporary storeage I'm haing problems.  I've read posts
that
> state that certain 2.4.X kernels have problems repecting the boundaries of
a
> ramdisk.  They tend to overwrite those areas when needing memory.
In all the work we did with ramdisks, I don't think we ever dd'd the img
directly
to the ramx device ... we always dd'd /dev/zero out to the size we wanted,
mke2fs'd it, then untar'd our package ... and we never had any problems with
that (in high 2.2.x's and low 2.4.x's too).


>
>
> lilo.conf:
> ....
>    root=/dev/ram7
>
> -----Original Message-----
> From: linux-mtd-admin at lists.infradead.org
> [mailto:linux-mtd-admin at lists.infradead.org]On Behalf Of Ian
> Sent: Tuesday, February 19, 2002 4:51 PM
> To: Chris Fowler
> Cc: linux-mtd at lists.infradead.org
> Subject: Re:Kerlen 2.4.13 and ramdisks
>
>
>
> If you have loopback support compiled in you can mount it directly through
> the loopback driver, without creating a ramdisk ...
>
> What was the error that mount gave?  You probably only need to specify
> the "-o" parameter ... mount doesn't usually detect fancy filesystems ...
>
>
>   ----- Original Message -----
> >From: "Chris Fowler" <cfowler at outpostsentinel.com>
> >To: <linux-mtd at lists.infradead.org>
> >Subject:  Kerlen 2.4.13 and ramdisks
> >Date: Tue, 19 Feb 2002 10:33:33 -0500
> >
> > You guys might have ran across a ramdisk problem.  I have a feeling that
> kernel 2.4.13 is
> not respecting my ramdisks.
> >
> >
> > dd if=/etc/user.img of=/dev/ram6
> >
> > mount /dev/ram6  fails.
> >
> >
> > Is this a problem?
> >
> >
> >
> >
> >
> > ______________________________________________________
> > Linux MTD discussion mailing list
> > http://lists.infradead.org/mailman/listinfo/linux-mtd/
> >
>
>
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